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Glass is important as a substrate for coatings in a wide range of applications or as a substrate for the fabrication of optical micro/nano structures. Coating by wet chemistry methods often demands modifications of the glass surface properties involving several steps. In addition, the micro/nano structuring is usually a several-step process. New methods that are simpler and more efficient are being proposed. One of them is glass poling that has been used to obtain surface relief on glass and, together with electric field assisted dissolution, for metal nanostructures in glass/metal systems. In this work, we demonstrate that poling increases the susceptibility of the glass surface for coating with Ag nanoparticles synthesized in situ by silver salt reduction. It is shown that a selectively poled glass surface can be used as a template to obtain optical microstructures consisting of Ag nanoparticles in only three simple steps. As a proof-of-concept, the method is used to fabricate diffraction gratings with an optical response that can be tuned by adjusting the Ag concentration. This approach is more versatile than the standard structuring by electric field assisted dissolution, as it does not require application of an elevated temperature once the coating is formed, which might change or destroy the properties of the thermally sensitive coating species or morphologies.

Despite a huge expansion of research on compositionally complex alloys, CCA (such as the entropy alloys, HEA and the corresponding glassy alloys) their comprehension is still limited, which is detrimental both for the design of CCAs and for their application. The broad compositional range in CCAs enables simple tuning of their properties by varying the contents of their constituent elements. Accordingly, the study of transition from CCA to conventional alloy, CA composed from the same constituents is important, both for understanding the formation of solid solutions in CCAs and for proper evaluation of their potential with respect to that of CAs. However, this transition has so far been studied systematically in only two types of alloys: isopleths of the Cantor alloy and glassy TiZrNbCuNi/Co alloys with variable Co, Ni or Cu content (Materials 14 (2021) 5824 and ref. therein). In both alloy systems the variation of a given property with composition depends sharply on the selected principal component and can be either monotonic (like that in the ideal solid solution) or non-monotonic. When the variation is non- monotonic, the maximum value of the selected property is usually outside of HEA composition range.

Since its discovery, graphene has become a very interesting material for the application in a variety of fields, such as photonics, plasmonics, spintronics or nanoelectronics. It is attracting ever growing interest due to its remarkable properties which have origin in graphene’s crystal and electronic structure. The electronic structure of graphene was resolved in angular-resolved photoemission (ARPES) experiments and its most characteristic feature is a Dirac cone. The Dirac cone could be modified in interaction with the substrate by charge carriers doping or by structural modification. We have studied a periodically modulated graphene grown on Ir(332) substrate where graphene growth induces reversible, well defined faceting of iridium surface into alternating terraces and step bunches which we investigated in scanning tunneling microscopy (STM) experiments [1][2]. Measurements of the electronic band structure by ARPES showed the Dirac cone anisotropy which was attributed to the 1D periodicity present in the system and lateral variation of the charge carrier concentration (on terraces and step bunches) [2]. [1] Šrut, Iva ; Mikšić Trontl, Vesna ; Pervan, Petar ; Kralj, Marko ; Temperature dependence of graphene growth on a stepped iridium surface.// Carbon 56 (2013) ; 193-200 [2] Iva Šrut Rakić, Marko Kralj, Wouter Jolie, Predrag Lazić, Wenhao Sun, José Avila, Maria- Carmen Asensio, Fabian Craes, Vesna Mikšić Trontl, Carsten Busse, and Petar Pervan ; Step-induced faceting and related electronic effects for graphene on Ir(332) // Carbon 110, (2016) 267-277

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Despite a huge expansion of research on compositionally complex alloys, CCA (such as the approximately equimolar, multi-component high- entropy alloys, HEA and the corresponding high- entropy glassy alloys), their basic understanding is still limited, which is detrimental both for the design of CCAs and for their application. In particular, the prediction of compositions capable of forming random solid solutions (RSSs) and the prediction of their properties is still a problem. Nevertheless, some properties of a few CCAs exceed those of conventional alloys (CA) [1].

Metal doped silica glass is widely used in photonics, photoelectronis, optics as well as in sensing. There are several methods for doping the glass matrix with metal ions, such as often used melted salt ion exchange and much cheaper and simpler process called electric field assisted dissolution (EFAD), used in our laboratory 1-3. In EFAD process, thin metal films deposited on glass substrate by electron beam evaporation are subjected to moderately elevated temperature and DC voltages. Resulting current induces several consecutive processes: 1) drifting of naturally present alkali metal ions in glass matrix toward cathode, leaving the subanodic layer depleted of charge carriers ; 2) dissolution of thin metal film and 3) subsequent travelling of dissolved metal ions into the subanodic layer. Unfortunately, the doping process is still not completely unveiled. Therefore, the elucidation of the process itself is extremely important. Herein we present ellipsometry based results of the optical properties of Al or Cu EFAD doped glass. Doping with metal ions and depletion from alkali ions are processes that take place simultaneously, but each with its own dynamics. As a consequence, the refractive index in the subsurface layer of the EFAD doped glass changes with the course of the process. Besides this, the refractive index is not constant through the thickness of the affected region since concentration of the dopant metal ions, as well as alkali ions, is not homogeneously distributed.

Various glass samples were poled using high temperature and electric field. Optical characterization and SIMS of samples were performed. SIMS measurements were compared to numerical simulations of atomic ratio depth profiles.

We present results of comprehensive study of electronic properties of (TiZrNbCu)(1-x)Ni(x) metallic glasses performed in broad composition range x encompassing both, high entropy (HE) range, and conventional Ni-base alloy concentration range, x >= 0.35. The electronic structure studied by photoemission spectroscopy and low temperature specific heat (LTSH) reveal a split-band structure of density of states inside valence band with d-electrons of Ti, Zr, Nb and also Ni present at Fermi level N(E_F), whereas LTSH and magnetoresistivity results show that variation of N(E_F) with x changes in Ni-base regime. The variation of superconducting transition temperatures with x closely follows that of N(E_F). The electrical resistivities of all alloys are high and decrease with increasing temperature over most of explored temperature range, and their temperature dependence seems dominated by weak localization effects over a broad temperature range (10-300 K). The preliminary study of Hall effect shows positive Hall coefficient that decreases rapidly in Ni-base alloys., 32 pages, 6 figures

In metallic systems electronic structure determines almost all their properties. Therefore, a change in properties of multicomponent alloys on crossing from HEA to conventional alloy concentration range in the same alloy system reflects the corresponding change in ES.

Electric field assisted dissolution (EFAD) is a process in which metal nanoparticles on the surface of the substrate dissolve and drift away from the anode into the bulk of the substrate under the influence of the applied electric field and moderately elevated temperature. There is a significant interest in EFAD due to its possibility to imprint the image of anodic electrode structure in glass- metal nanocomposites. EFAD can also be utilized for developing novel bio-, chemical and environmental sensors. Recently, microstructuring of conductive thin silver layers have been obtained using EFAD. Copper and aluminium are materials interesting for microstructuring because of their good conductivity, they are abundant and consequently, relatively cheap. It would be useful to find the maximum conductive microstructure thickness that can be achieved by reasonable EFAD conditions using these materials. For this purpose, copper, aluminium, and silver thin layers were deposited onto soda-lime glass substrate using electron beam evaporation. Different magnitudes of electric field, temperature and duration of EFAD were applied to these layers. Measurements of the obtained samples optical properties is done by ellipsometry followed by optical characterization. The limitations of EFAD process applied for microstructuring of conductive metal layers, same as guidelines for further research were obtained. Therefore could be used for photocurrent enhancement. With the spin coating method, we synthesized gold, silver and copper nanoparticles on a glass substrate. Combining different ratios of different metal precursor salts it is possible to obtain interesting optical properties. By changing the temperature and time of annealing of the substrates as well as the metal salt concentration and a choice of a solvent for the spin coating, it is possible to manipulate the shape and size of metal nanoparticles on the substrate.

The study of transition from conventional concentrated alloys to high-entropy ones composed from the same elements is apparently very important, both for understanding the formation of HEAs and for proper evaulation of their potential with respecct to that of corresponding CAs.

We present the results of ongoing comprehensive study of the electronic properties of (TiZrNbCu)1- xNix metallic glasses performed in a broad composition range x encompassing both, the high entropy (HE) range, x ≤ 0.25, and conventional Ni- base alloy concentration range, x ≥ 0.35. The electronic structure (ES) studied by photoemission spectroscopy and low temperature specific heat (LTSH) [1] reveal the split-band structure of the density of states (DoS) inside the valence band with the d- electron of Ti, Zr, Nb and also Ni present in DoS at the Fermi level N(EF), whereas LTSH and present magnetoresistivity results show that variation of N(EF) with x changes in Ni-base regime. The variation of the superconducting transition temperatures, TC ≤ 1.6 K with x closely follows that of N(EF) as is usual in disordered transition metal alloys [2]. The electrical resistivities of all alloys are high (> 150 µΩ cm) and accordingly decrease with increasing temperature over most of the explored temperature range, and their temperature dependence seems dominated by the weak localization effects over a broad temperature range (10 – 300 K). The preliminary study of the Hall effect shows that the Hall coefficient RH > 0 and in the HE concentration range change little with x. The results are compared with these for corresponding binary metallic glasses. [1] I. A. Figueroa, et al., J. Alloys Compd. 745, 455 (2018) [2] E. Tafra, et al., J. Phys.: Condens. Matter 20, 425215 (2008)

On cooling of molten alloy the formation of metallic glass (MG) competes with that of intermetallic compounds (TC). This competition determines glass forming ability (GFA) of a given alloy and in binary alloys GFA can be expressed in terms of the formation enthalpies of MG and competing TCs [1]. More recently we have shown that a similar electronic structure, ES, (represented by the density of states (DoS) at the Fermi level, N(EF)) of competing TCs to that of MG enhances GFA in Cu-Hf, Zr alloys [2]. In particular, we found that small difference between the N(EF)-dependent properties (such as magnetic susceptibility (χ) and Sommerfeld coefficient (γ)) of as-cast and crystallized MGs reflects an enhanced GFA. Combining our and literature results for N(EF) and χ we show here that this correlation holds in all binary (Cu, Ni-Ti, Zr, Hf) and ternary (Cu-Hf-Ti, Cu-Zr-Al) alloys of early (TE) and late (TL) transition metals for which there exist relevant data. The correlation between ES and GFA shows up the best in Cu-Zr and NiZr2 alloys in which the data for change in N(EF) upon crystallization exist. The applicability of this correlation (GFA criterion) to all TE-TL alloys is supported by photoemission studies and low temperature specific heat measurements [3] which show similar composition dependencies irrespective of the number of components in the alloy. _____________________________________________ ∗ This work was supported by UNAM-DGAPA-PAPIIT project No. IN101016 and Osijek University project IZIP2016-3. † [1] R. Ristić et al., J. Alloys and Compd. 621 (2015) 136 ; [2] K. Biljaković et al., J. Alloys Compd. 695 (2017) 2661 ; [3] R. Ristić et al. EPL , 114 (2016) 17006.

High-entropy alloys (HEA) are new type of alloys based on multiple (≥5) principal alloying elements [1). This design enables research and probable exploitation of a huge number of new alloys with structures and properties which can hardly be anticipated [2]. For obvious reason and also due to often inadequate strategy of research [3], the conceptual understanding of HEA is quite limited which hampers their development. After brief introduction in HEA we present main results of a parallel study of local atomic structure, electronic structure (including first ever photoemission spectroscopy study of HEA) and selected properties of (TiZrNbCu)1-xNix (x≤0.5) amorphous alloys, which sheds more light into their interrelationship and also enables direct comparison of HEA with conventional Ni-rich alloys (x≥0.35). Our results challenge some myths commonly employed in descriptions of HEA [2]. [1] B. Cantor, I. T. H. Chang, P. Knight, A. J. B. Vincent, Mat. Sci. Eng. A 375-377 (2004) 213. [2] E. J. Pickering, N. G. Jones, Inter. Mater. Rev. 61 (2016) 183, and references therein. [3] K. Biljaković et al , J. Alloys Compd. 695 (2017) 2661.

Termoodskočni materijali su materijali koji bi jednog dana mogli omogućiti pretvaranje termalne energije u mehanički rad na nanoskali. Grijanjem ili hlađenjem ove materijale dovodimo do naglih i oštrih polimorfnih faznih prijelaza s očuvanjem integriteta jediničnih kristala. U tom se procesu mijenja oblik kristala i veličina jedinične ćelije. Ta promjena je toliko intenzivna da kristali skaču na visine i do tisuću puta veće od njih samih. Trajanje ovog efekta je nekoliko mikrosekundi. Termoodskočni materijali imaju veliki diskontinuitet u promjeni volumena jedinične ćelije tijekom faznog prijelaza. Uočeno je da je piroglutaminska kiselina (eng. - pyroglutamic acid) ili skraćeno PGA termoodskočni materijal. Za potrebe ovog rada proučavana je L-PGA, kiralna forma PGA. Ispitivani su visokotemperaturni fazni prijelazi α → β i β → α. Naša mjerenja su potvrdila rezultate prijašnjih istraživanja. Tijekom faznih prijelaza kristali PGA skaču u zrak, uz očitu promjenu vanjskih dimenzija. Thermosalient materials are materials which in future could enable us to transform thermal energy to mechanical work at nanoscale. We bring these materials to sudden polymorphous ”monocrystal to monocrystal” phase transitions by heating or cooling them. Shape of the crystal and size of the unit cell are changed in that process. That change is so intense that crystals jump to the heights thousand times higher then themselves. This effect usually happens in a matter of miliseconds. Thermosalient materials have a great discontinuity in the unit cell change in volume during the phase transition. It was noticed that pyroglutamic acid or PGA is a thermosalient material. In this study L-PGA, chiral form PGA was investigated. We have examined high temperatures phase transitions α → β i β → α. Our measurements confirmed the results of previous studies. During phase transitions the crystals of PGA jump in the air with obvious change in overall size.

The study of producing graphene extends from mechanically exfoliated graphene fl akes transferred to diff erent substrates to chemical vapor deposition (CVD) growth process on diff erent metal surfaces. The most frequently used carbon source in CVD process is ethylene. To obtain a single domain (R0) graphene on Ir(111) surface from ethylene high growth temperature (~1000°C) is required. As already reported, reduction of growth temperature is realized by using aromatic carbon sources in CVD process on Cu(111) in the region of atmospheric pressure [1]. The use of benzene reduces the growth temperature as low as 300°C. This fi nding opens the opportunity to the possibility of low temperature growth on Ir(111), but in ultra high vacuum (UHV) conditions. To investigate this possibility we used scanning tunneling microscopy (STM) and low energy electron diff raction (LEED). Our fi ndings point to the CVD growth with predominantly R0 oriented graphene achieved at 700°C.

Termoodskočni materijali su materijali koji bi jednog dana mogli omogućiti pretvaranje termalne energije u mehanički rad na nanoskali. Grijanjem ili hlađenjem ove materijale dovodimo do naglih i oštrih polimorfnih faznih prijelaza s očuvanjem integriteta jediničnih kristala. U tom se procesu mijenja oblik kristala i veličina jedinične ćelije. Ta promjena je toliko intenzivna da kristali skaču na visine i do tisuću puta veće od njih samih. Trajanje ovog efekta je nekoliko mikrosekundi. Termoodskočni materijali imaju veliki diskontinuitet u promjeni volumena jedinične ćelije tijekom faznog prijelaza. Uočeno je da je piroglutaminska kiselina (eng. - pyroglutamic acid) ili skraćeno PGA termoodskočni materijal. Za potrebe ovog rada proučavana je L-PGA, kiralna forma PGA. Ispitivani su visokotemperaturni fazni prijelazi α → β i β → α. Naša mjerenja su potvrdila rezultate prijašnjih istraživanja. Tijekom faznih prijelaza kristali PGA skaču u zrak, uz očitu promjenu vanjskih dimenzija.